Metalliferous azo-dyestuffs



Patented Oct. 2, 1951 2,570,085 METALLIFEROUS AZO-DYESTUFFS Willi Widmer, Bottmingen, and Arthur Buehler, Rheinfelden, Switzerland, assignors to Ciba Limited, Basel, Switzerland, a Swiss firm No Drawing. Application March 2, 1948, Serial No. 12,685. In Switzerland March 7, 1947 7 Claims. 1 'According to this invention valuable new metalliferous azo-dyestuffs are made by treating with an agent yielding metal an azo-dyestufi of the general formula in which R represents the radical of a coupling component bound to the azo linkage in a position vicinal to a hydroxyl group, and X represents a hydrogen atom or an alkyl group, and, when X represents an alkyl group, conducting the treatment under conditions such that the said alkyl group is split ofi.

The monoazo-dyestufis used as starting materials in the present invention which have the formula As examples of coupling components yielding azo-dyestuffs especially suitable as starting materials in the present process there may be mentioned: hydroxynaphthalenes such as an-naphthol, p-naphthol, 1:3-dihydroxynaphthalene, 2:3- dihydroxy'naphthalene, 2 B-dihydroxynaphthalene, 2:7-dihydroxynaphthalene, 2:6- or 2:7-hydroxy-methoxy-naphthalene, 1-acetylamino-7- hydroxynaphthalene, 5 B-dichloro-l-hydroxynaphthalene, 5-chloro-hydroxynaphthalene, 1- hydroxy-4-methylnaphthalene, 1-hydroxy-4-nbutylnaphthalene, l-hydroxynaphthalene-4- or -5-sulfonamide, l-hydroxynaphthalene 8 sulionamide, 1-hydroxynaphthalene-8-sulfonic acid, l-hydroxynaphthalene-lor -5-sulfonic acid; 5- pyrazolones such as 1-phenyl-3-methy1-5 py'-' razolone, 1(2'-chloro) -pheny1-3-methyl-5 pyrazolone, l-(2'-naphthyl) -3-methyl-5-pyrazolone, 1-(3'-sulfo)-phenyl-3-methyl 5 Dyrazo lone, 3-methyl-5-pyrazolone, 1-(4-sulfo) phenyl-5-pyrazolone-3-carboxylic acid, 1:3-diphenyl- 5-pyrazolone,1-phenyl-5-pyrazolone-B-carboxylic acid amide; and also resorcinol, perinaphthindane-dione, acetoacetic acid anilide, barbituric acid, N-ph'eny1-4-hydroxy-2-quinolone, 2:4-dihydroxyquinoline, meta-phenylene diamine, 1- hydroxy-3-aminobenzene, l-methyl-Z-amino 4- hydroxybenzene and 2-hydroxyanthracene.

Of the hydroxynaphthalenes, there are particularly useful in this connection the 1- and 2- hydroxynaphthalenes and the hydroxymonosul- Ionic acids which carry no additional substituents; and of the 5-pyrazolones, the l-phenyl- 3-methyl-5-pyrazolones are especially suitable.

Valuable metalliferous disazo-dyestufis can yielding metal.

Among the azo-dyestufis used as starting ma terials in the present process there are especially valuable those of which the alkoxy group (present in the radical of the l-amino-2-hydroxy-61- alkokynaphthalene- -i-sulfonic acid) contains only a few carbon atoms as, for example, in the case of dyestuffs obtained from diazotized l-amino- 2 -hydroxy-6-ethoxynaphthalene-4 sulfonic acid and principally from diazotized 1-amino-2- hydroxy-G-methoxy naphthalene 4 sulfonic acid.

The 1-amino-2-hydroxy-6-alkoxynaphthalene- 4-sulfonic acids, from which the azo-dyestuffs used as starting materials in the present process may be made, may be prepared in the following manner:

By treating a 2-hydroxy-6-alkoxynaphthalene with a nitrosonating agent (for example, an alkali nitrite and a mineral acid) there is formed a 1-nitroso-2-hydroxy-fi-alkoxynaphthalene, and the latter compound converted by the action of a solution of an alkali bisulfite into Z-hydroxy- 6 alkoxy-l-naphthyl hydroxylamine sulionic acid. By heating the latter in a. medium rendered acid with mineral acid the des'ired'l-amino-2-hydroxy-6-alkoxy naphthalene-i-sulfomc acid is obtained.

The diazotization of the 1-amino-'2=hydroxy-6- alkoxynaphthalene-4-su1fonic acids is carried out in a manner known for compounds .of this kind, that is to say, for 1:2- or 2:1-amino-hydroxynaphthalenes, for example with the aid of sodium nitrite in the absence of a free mineral acid and in the presence of an equivalent quantity of a zinc salt or a small quantity of copper sulfate. Theresulting diazo-compou-nds may, for example, be separated from the diazotization mixture by the addition'of a mineral acid or sodium chloride, filtered and, if desired, dried. In this form they are stable products.

The coupling of the diazotized 1-amino-2-hydroxy-G-alkoxynaphthalene-fl-sulfonic-acids may likewise be carried out by methods 'in themselves known. It is generally carried out with advantage in an alkaline medium, for example, a medium rendered alkaline with an alkali carbonate to alkaline with caustic soda, if desired, in the presence of a suitable solvent, such as'alcohol or pyridine, capable of assisting the coupling, or in the presence of an agent yielding metal, among which may be mentioned, for example, an agent yielding copper or yielding'zinc, such as zinc chloride. These agents yielding metal maybe used for assisting the coupling and, ifdesired, removed from the dyestufi after coupling when it is desired to form aco'mplex with a different metal.

The treatment of the dyestuff with an'agent yielding metal, in accordance with this invention, may be carried out, for example, with an agent yielding iron, nickel, cobalt,- aluminium or copper. However, valuable products are principally obtained by treatment with an agent yielding chromium.

As agents yielding chromium there come into consideration practically all the chromium compounds which are customarily used for converting azo-dyestuiis into complex chromium com pounds, thus, especially salts of trivalent chromium such as the acetate, formate andpreferably the fluoride or sulfate. The treatment may be carried out with advantage in an aqueous medium, in the presence or absence of an organic solvent such as alcohol or pyridina'in an alkaline, neutral or acid medium, if desired, with the addition of a" substance capable of forming complexes, such as an aliphatic or aromatic hydroxy-carboxylicfacid, and, if desired, under atmospheric or superatmospheric pressure. In most cases it is ofadvantage touse' 1 atomic proportion 01 chromium-or a; certain'excessfor eachmolecular proportion-of dyes'tuffi The complex metal compounds, and-especialiy the complex chromium compounds, obtainable by the present process can, however, also be made by starting from an azo-dyestuff of the general formula in which It represents the radical of a coupling component bound to the azo linkage in a position vicinal to a hydroxyl group, and carrying out the treatment with an agent yielding metal under conditions such that the alkyl group, which is present in the O-alkyl group in the position vicinal to the azo linkage, is split off.

' conditions.

This can be brought about, for example, by treating the dyestuff with an agent yielding metal, for example,an agent ielding copper such as a copper tetramine salt, under energetic reaction In this connection there comes into consideration, above all, treatment with an agent yielding chromium, for example, treatment with chromium sulfate or chromium formate in an aqueous medium under pressure and at .a raised temperature, for example, a temperature rang ing from C. to C. The-azo-dyestuffs of the above formula serving as starting materials in the latter form of the process may be obtained by methods in themselves known from a diazotized 1 amino-i2:B-dialkoxynaphthalenel-sulfonic acid and a coupling component which couples in a position vicinal to a hydroxyl group. As coupling components there may also be used in this connection :the compoundshereinbefore named as coupling components; and further.- more coupling components such, for example, z-hydroxynaphthalene-8sulfcnic acid or Z -hydroxynaphthalene-G:8-disulfonic acid, which do not couple or couple with difficulty withyorthm hydroxy-diazo-compounds. 'l-amino 2:6 dialkoxy-naphthalene-4-sulfonic acids may be obtained from 2 :6-dialkoxynaphthalenes, for exam:- ple, from 2:B-dimethoxynaphthalene, by mumtion, reduction of the nitro-compound to the amino-group, and sulfqnation.

The new products obtainable by one of the two foregoing processes are complex metal compounds of dyestuffs oI the general formula in which R represents the radical of a coupling "component bound to-the aao linkage inapos'iticn those of the monazo dyestuffs of the general for-- in which R. represents the radical oi:

-acid bath fast greenish blue naphthalene bound to the azo linkage in a pcsi tion vicinal to a hydroxyl group, or the radical of a S-pyrazolone bound to the azo linkage in the 4-position.

The complex metal compounds obtainable by the invention, and above all the complex chromium compounds, are suitable for dyeing various materials, particularly those of animal origin, such as casein or gelatine, and principally for dyeing or printing animal textile fibers, such as wool, silk or leather, and also fibers having similar dyeing properties such as artificial wool from casein fibers, animalizedrcellulose artificial silk, and, if desired, for dyeing and printing artificial fibers of superpolyamides or superpolyurethanes.

In this manner there are obtained valuable, level and generally very pure dyeings having good properties of fastness. .As compared with dyebags produced with dyestuffs of similar constitutainable with these known dyestuffs by the substantially better shades of their dyeings when viewed in artificial light.

The following examples illustrate the invention, the parts and percentages being by weight:

Example 1 14.3 parts of 2-hydroxynaphthalene are dissolved in 25 parts of water with the addition of 5.6 parts of potassium hydroxide and 6.9 parts of potassium carbonate. About 30 parts of, ethyl alcohol are then added, and the whole is cooled to 10-12 C. The diazo-compound obtained from 26.9 parts of 1-amino-2-hydroxy-6-methoxy- 'naphthalene-i-sulfonic acid is introduced in small portions into the solution in the course of one hour. After 12 hours the whole is heated to 30-35 C. and stirred at that temperature until the formation of dyestufi has ceased. The resulting dyestuif which corresponds to the formula OH OH 'N: soIH is. separated by filtering with suction, and, if desired, purified by dissolution in water, reprecipitation with sodium chloride and filtration.

The dyestufi so obtained is boiled under refiux for 24 hours in 1500 parts of a chromium fluoride solution containing a. quantity of chromium corresponding to- 9.5 parts of Cr203. The resulting complex chromium compound, which is almost insoluble even in hot water, is separated by filtration, washed with hot water, and converted in known manner into its easily soluble sodium salt. The latter is precipitated by the addition of sodium chloride, and then separated by filtration and dried. The dyestufi is a violet blackpowder 'which dissolves in water with a blue violet coloration and in sodium carbonatesolutio'n with a blue coloration, and dyes wool from a sulfuric The diam-compound of 1-amino-2-hydroxy-6- methoxynaphthaleneei-sulfonic acid may be prepared as follows:

17.4 parts of 2-hydroxy-6-methoxynaphthalene are dissolved in 150 parts of water and 4 parts of sodium hydroxide at 50 C. 6.9 parts of sodium nitrite are added, and the whole is cooled to 0 C. by the addition of to 150 parts of ice. 32 parts of sulfuric acid of 40 per cent strength are then added dropwise in the course of 3 hours, while stirring, the temperature being maintained at 0-3 C. by indirect cooling. The reaction mixture is maintained at that temperature for a further 2 hours, and the resulting 1-nitroso-2'-hy'- droxy-G-methoxynaphthalene is separated by filtering with suction and washed free from acid with ice-water. The nitroso-compound so obtained, corresponding to the formula OOH2.

quantity of dilute sulfuric acid obtainedfrom 20 parts of concentrated sulfuricacid of about 96 per cent. strength and 40 parts of ice. After 2 hours the whole is slowly heated to 50? 0., whereupon l-amino-2-hydroxy-6-methoxynaph- -thalene-4-sulfonic acid which corresponds to the formula NHz OCH:

separates in the form of a pale grey compound. The compound is separated by :filtration, and washed neutral with cold water. When dry it i a pale grey powder which dissolves easily in dilute alkalies.

26.9 parts of 1-amino-2-hydroxy-G-methoxynaphthalene-i-sulfonic acid are suspended in parts of water with the addition of 2 parts of crystalline copper sulfate, and the suspension is cooled to 0 C. A solution of 6.9 parts of sodium nitrite in 25 parts of water is added dropwise, and the whole is stirred for a further hour at 0-5 C. The resulting solution is freed from a small quantity of precipitated matter by filtration, the residue is washed with 100 parts of water, and the whole of the filtrate is mixed with 26.6 parts of hydrochloric acid of 30 per cent. strength. The diazo-compound of 1-amino-2- hydroxy-6-methoxynaphthalene-4-sulfonic acid precipitates in the form of its pale yellow sodium salt. The latter is separated by filtering with suction and may be dried under reduced pressure at 60-70 C.

.m nm corresponding .to .95 parts of E am le 2' 22.4 parts of l-hydroxynaphthaleneA-sulfonic sold re d ss ed i .50 part w ter w h t additi n o .5- part o potass ii ll hyd x e a d 6-9 ar of o a um carbonat Into t e 1 Sel n solution is trodu ed, '1 t e course 9H ho r M2 C- diazo com ound Pbi iii tl $.1 261-9 parts 1 .1fam n -z-h dmxyfi-methqxy nap thalenei-sulip ii? id- Wh 1%? 99.

a ed t dy tufi obtained is 9. .1!-

Pline has 11 8 3 precipi a ed y c ific tion r by 1.

addi ion of potassium chloride and separated by filt at n rr spond n, he i rmrls OH on SOsH soar: don:

The dyestufi so obtained is Jaoiled for 24 hours under reflux in 1000 partspf a chromium formate solution which contains a quantity of chromium corresponding to 9.5 parts of CIzOx. The solution is filtered hot to remove impurities, and the complex' chromium compound is precipitated fromthe filtrate by the addition of sodium chloride pand then separated by'filtration and dried. I

The dyestufi is a blue-black powder having a bronze luster which dissolve in water with a blue coloration and in concentrated sulfuric acid with a green-blue coloration, and dyes wool from. a sulfuric acid bath blue tints.

Example 3 Asolution of 25.4 parts of 1.-.- (.4-'.=su1fo )-,-phenyl 3-methyl-5-pyrazolone, 4 parts of sodium -hy-- .droxide and 5.3 parts of sodium .carbonateinz50 parts of water is cooled .to 10 .C. while stirring. The diazo-compound from 26.9 pants of -1 -amino- 2-hydroxy-6-methoxy-naphthalene 4 .sulfonic acid is introduced in the course of 2 hours while stirring. When the coupling has ceased the whole is heated to 50C., neutralized with hydrochloric acid and the resulting dyestufi is precipitated by theadditionzof sodium chloride and separated by filtration. It corresponds to the formula The dyestufi so obtained is boiled forge-hours .under reflux in 1200 parts of a pnromium suljate solution which cpntains a gua tity of chrps ut n is cl rified try-fi rat on tbsm- ;r ex .chrom u comp und i rec ita e, the fi trat b th d i n .of s diu 1 gthgl' separated oy-fi tra onsnl ie i h r .stufir saB rd anss n ws sn h sl isfi iin -.w.at r w a e -vi e co r t on an 1. ce tra e su ur i h an o an e huma s d es oq i r m a sul ii es ver ure -riole tin sl ev isis dir tfln e of ,fastness.

, tion which contains a quantity of ch'r o 1 A dream savin amnesia is; ies n he terms is obtained by startingfrom 1-(3 -sulfo).-.phenyl 3-methyl-5-pyrazolone, instead of 1-(4'-sulfo)r phenyl- 3-methyl=5-pyrazolone and in other re-zspects iollowi-ng the procedure described above.

sam l 4 The dxest r s o tained is b e r 2% were u r .r fln s dil t hr m o id corresponding to 9.5 parts of Crj O 'l The 'r n complex chromium compound, after h worked up 1; e usual manner, is, in the state Tia Bordeaux red powder which dyes w v 1 iron sul uric Example 5 22.4 parts of 1-hydroxynaphthalene-8-sulfonic acid are dissp lyed ifi so parts of water with the addition of 11:2 parts of potassium hydroxide. Into this solution is introduce d'at 20 C. in the course of 1 hour the-diazo comppund from 26.9 parts of 1 amino-Z-hydroxy 6 methoxynaphthalene-l-sulfonic acid. When the coupling has ceased h r ulting .dyestnfi rwhiqh .q t ssee s 3 95. 1 .Th s yss haste s hta ned is fl oded o :2

i sfiomp te nsecipitatedlby the add tion o po- -.c1 .1ori.d and separated .by filtration.

. qurs 1- ire ux -199 .nartso chromium fluo id solutio 9h .0 am .a Quan ty. iQ

chromium qrsesp n h s-110.95 part .o qljQg.

a id no 1 ed-rider ,aszaoss The solution filtered hot, and the complex chromium compound is precipitated from the filtrate by the addition of sodium chloride, separated by filtration and dried. Thedyestufi is a blue-black powder which dissolves in water with a blue coloration and in concentrated sulfuric acid with a green-blue coloration and dyes wool from a sulfuric acid bath pure greenish blue tints.

Example 6 28.3 parts of 1-amino-2:G-dimethoxynaphtha- 1ene-4-sulfonic acid (obtained from 2:6-dimethoxynaphthalene by nitration, reduction of the nitro compound and baking the sulfate of the base) are dissolved in water with the addition of 5.3 parts of sodiumearbonate. To thesolution having a green fluorescence are added 6.9 parts of sodium nitrite in 50 parts of water, and the temperature is brought to C. By pouring the solution into a mixture of 30 parts of hydrochloric acid of 30 percent. strength and 120 parts of water'the diazo compound is obtained in the form ofa sparingly soluble pale yellow body, which is then separated by filtration and introduced in the course of 2 hours into a cooled solution of 25.4 parts of 1-(3'-sulfo)-phenyl-3- methyl-5-pyrazolone, 4 parts of sodium hydroxide and 5.3 parts of sodium carbonate in 200 parts of water. When the couplinghas ceased the dyestufi which corresponds to the formula I OCH \C N 3 151?! HaOO- a quantity of chromium corresponding to 9.5

parts of CIzOa. The resulting complex chromium compound of the dyestuff corresponding to the formula HaCO tained. as described in the third paragraph of Example 3. It dyes wool bath red-violet tints. By treating with chromium sulfate in the manner described above the dyestufi obtained by coupling diazotized 1 amino 2:6 dimethoxy naphthalene-ii-sulfonic acid with Z-hydroxynaphthalene, there is obtained a chromiferous dyestuif which correspondsto the dyestufi obtainable' asdescribed in Example 1.

Example 7 11 parts of 1:3-dihydroxybenzene are dissolved in 75 parts of water with the addition of 11.2 parts of'potassium hydroxide, and the whole is brought to 0 C. by external'cooling. 'The diazo compound obtained from 26.9, parts of 1 -amino- 2 hydroxy 6 '-"methoxynaphthalene 4 sulfonic acid isintroduced into the resulting solution in the-course of'j 2flhours in small por tions. When the coupling has ceased, the dye stuff obtainedis'precipitated by the addition of 11.5 parts ofhydrochloric acid of 30 per cent. strength and sodium chloride, separated by filtration and if desired, .j'purified by dissolution in water and reprecipitation with sodium chloride.

The monoazo dyestuff so obtained is dissolved in 300 parts of water with the addition of 5.6 parts of' potassium"hydroxide and 6.9 parts of potassium carbonate, and the whole is brought to a temperature of 5' C. by indirect cooling, and coupled with the diazo compound obtained in known manner'from 15.4 parts of 4-nitro-2- amino-l-hydroxybenzene. When the coupling has ceased the whole is'hea'ted to 60 C., and the dye'stulfso obtained is precipitated bythe addition of sodium chloride, separated by filtration and dried. It is a green black powder which dissolves in water-and insodium carbonate solution with a grey-black coloration and in concentrated sulfuricacid with'a dark green coloration.

The disazo dyestufl so obtained is boiled under reflux for 20-.hours'with 1000 parts of a chromium sulfate solution containing-a quantity of chromium correspondingto 19 .parts of C1203. The solution is; filtered while hot to remove impurities, the complex chromium compound is precipitated by the addition of sodium chloride, separated by filtration and dried. It is a black powder which dissolyeskin water and in concentrated sulfuric acid with a dark green coloration and dyes box calf greenish black tints.

from a sulfuric acid Escample 8 55.5 parts of the disazo dyestufi obtained ac:- cording to "the first and second paragraphs of Example 7 are dissolved in 1000 parts of water with'24.6 parts of ,SQdium acetate. 25 parts of crystallized copper sulfate dissolved in a small quantity of water are then'added. After stirring for 6 hours at -,85 C. the reaction mass is filtered whilewarm to remove impurities and the complex copper compound separated by the addition of sodium chloride,,' filtered and refluxed for 20 hours with 500'parts of a chromium sulfate solution containing the quantity of chromium which corresponds-to 9.5 parts of CrzO3. Impurities are removed by filtering the hot solution before the complex copper-chromium compound is precipitated by the addition of sodium chloride, filtered and dried. The compound is a black powder which dissolves in water to give a reddish Example 9 100 parts of well wetted wool are entered at 40 C. into a dyebath which contains in 3000 parts of water 1.5 parts of the chromife'rous dyestuff obtainable as described in Example 1 and 40 parts of sulfuric acid of 10 per cent. strength, and the bath is slowly heated to the boil. After boiling for ,4 hour a further 40 parts of sulfuric acid of 10 per cent. strength are added, and dyeing is continued at the boil for 1 hours. The wool is then rinsed in the usual manner and finished. It is dyed a fasVg'reenish-blue tint, the pure appearance of which is maintained in artificial light.

Having thus described the invention, what is claimed is:

1. A complex chromium compound oi a monoazo dyestufi' of the general formula in which R stands for a. member selected from the group consisting of a radical of a hydroxynaphthalene bound to the azo linkage in a posiam tion vicinal to a hydroxy group, and a radical of a fi-pyrazolone bound to the am linkage in the 4-position. 2-. A complex chromium compound ofa monoazo dyestufi of the general iorm-ula N=N4R 03H in which R stands'for the radical of a hydroxynaphthalene bound to the azo linkage in a position vicin'al to 'a hydroxyl group.

'3. A complex chromium compound of a 'monoazo dyestufi of the general formula in which R stands for the radical of ya in which R. stands torthe radical oi a l-phenyl- 3-methyl-5-pyrazolone bound to the azo linkage in the 4-position.

5. A complex chromium compound of the t monoazo dyestufi of the formula l5 0,11- 6. A complex chromum compound of the monoazo clyestufr or the formula Y .OyH

, OiH "7. A complex chromium compound of the monoazo dyestuif of the formula I 7 CH.

v (in Hie-o w l 03H WILLI WIDMER. ARTHUR 'BUEHLER. REFERENCES CITED The following references are of record inthe file f this patent:

UNITED "STATES PATENTS 50 Number Name Date 1,676,697 Kaltwasser etal. July 10,1928 1,921,337 Wiedemann et al. Aug. 8,1933 1,921,586 Sack 1 .Aug.- 8, 1933 1,989,568 Straub et a1 Jan. 29, 1935 5 1,990,257 Stla'ub et a1 Feb. 5, 1935 7 1,993,462 Straub et a1. Mar. 5, 1935 2,008,601 Straub etal. July 16, 1935 r 2,452,171 straub en 91. Oct. 26, 1948 

1. A COMPLEX CHROMIUM COMPOUND OF A MONOAZO DYESTUFF OF THE GENERAL FORMULA 